阅读说明：本技术 传感器密封工艺 (Sensor sealing process ) 是由 赵川 董小刚 于 2021-09-10 设计创作，主要内容包括：本发明公开的属于传感器技术领域,具体为传感器密封工艺,包括电路板、注胶孔、金属罩和排气孔,具有操作步骤如下：S1：电路板上端装配有传感器,在压力感应单元外侧套接一个金属罩,金属罩下端连接电路板表面；S2：金属罩上端分别开设注胶孔和排气孔,注胶孔设置在传感器顶部；S3：将注胶针头对准传感器顶部的注胶孔,轻踩自动点胶机踏板,将适量的胶水通过注胶针头灌入注胶孔内,胶水通过注胶孔进入金属罩内部,对金属罩内部空间进行填充,胶水挤压金属罩内部空气,本发明有益效果是：通过在普通不点任何胶的工艺基础上,封装双开口铁壳防护,然后灌胶,可以有效的包裹焊盘和金线,只露出压力感应单元,全面的隔绝水汽。(The invention discloses a sensor sealing process, belonging to the technical field of sensors, comprising a circuit board, a glue injection hole, a metal cover and an exhaust hole, and comprising the following operation steps: s1: the sensor is assembled at the upper end of the circuit board, a metal cover is sleeved outside the pressure sensing unit, and the lower end of the metal cover is connected with the surface of the circuit board; s2: the upper end of the metal cover is respectively provided with a glue injection hole and an exhaust hole, and the glue injection hole is arranged at the top of the sensor; s3: the glue injection needle is aligned to the glue injection hole at the top of the sensor, the pedal of the automatic glue dispenser is lightly stepped, a proper amount of glue is injected into the glue injection hole through the glue injection needle, the glue enters the metal cover through the glue injection hole, the inner space of the metal cover is filled, and the glue extrudes the air in the metal cover, so that the invention has the beneficial effects that: through on ordinary not some any technological basis of gluing, the two opening iron-clad protections of encapsulation, then the encapsulating can effectual parcel pad and gold thread, only exposes the forced induction unit, comprehensive isolated steam.)

1. The sensor sealing process comprises a circuit board (1), a glue injection hole (2), a metal cover (3) and an exhaust hole (4), and is characterized by comprising the following operation steps:

s1: the sensor is assembled at the upper end of the circuit board (1), the metal cover (3) is sleeved outside the pressure sensing unit, and the lower end of the metal cover (3) is connected with the surface of the circuit board (1);

s2: the upper end of the metal cover (3) is respectively provided with a glue injection hole (2) and an exhaust hole (4), and the glue injection hole (2) is arranged at the top of the sensor;

s3: aligning a glue injection needle head to a glue injection hole (2) at the top of the sensor, lightly stepping on an automatic glue dispenser pedal, injecting a proper amount of glue into the glue injection hole (2) through the glue injection needle head, enabling the glue to enter the metal cover (3) through the glue injection hole (2), filling the inner space of the metal cover (3), extruding the air in the metal cover (3) by the glue, discharging the air through an exhaust hole (4), checking whether the glue completely covers the sensor or not, and putting the circuit board (1) in order after the correctness is confirmed;

s4: placing the circuit board (1) with the dispensed glue on a baking and placing frame, pushing the baking and placing frame with the dispensed products into a baking box, and turning on a power supply of the equipment according to the requirement of an equipment operation instruction;

s5: after glue inside the metal cover (3) is cooled and dried, firstly smearing thinner three-proofing paint on the joint of the bottom of the metal cover (3) and the circuit board (1) once to ensure that no bubbles appear around the sensor, after 1 hour, smearing undiluted three-proofing paint again, smearing the three-proofing paint on the outer wall of the metal cover (3), injecting glue into the glue injection hole (2) for blocking, and standing for 2 hours to be completely dried;

s6: adjusting the magnification of a microscope to 15-20 times, placing the circuit board (1) which is painted and placed for more than 2 hours under the microscope to check whether bubbles exist in sealing glue and painting on the surface of the sensor, marking a check mark at a specified position of the circuit board (1) after the check is qualified, and marking and distinguishing defective products and recording defective products.

2. The sensor sealing process of claim 1, wherein in S3, the glue discharging time of the glue dispenser is set to 2S, and the air pressure is set to 20-25 PSI.

3. The sensor sealing process of claim 1, wherein in S3, the glue injection needle does not contact the sensor, and the glue injection needle is pressed down on the pedal of the glue dispenser to completely cover the glue in the sensor, so as to ensure that the glue completely covers the sensor hole.

4. The sensor sealing process according to claim 1, wherein in the step S3, the glue ratio is 1:1, and the stirring time is not less than 2 minutes after the glue ratio is matched.

5. The sensor sealing process according to claim 1, wherein in S3, after the circuit board (1) passes the self-inspection, the circuit board (1) is placed on an anti-static partition plate and left to stand for cooling.

6. The sensor sealing process according to claim 1, wherein in the S4, the circuit boards (1) are sequentially arranged in a baking rack level and are not stacked.

7. The sensor sealing process of claim 1, wherein in S4, the oven door must be closed and fastened during the baking operation.

8. The sensor sealing process according to claim 1, wherein in S4, the baking oven is set at a temperature of 60 ℃ for 1 hour, and then set at a temperature of 80 ℃ for 2 hours.

Technical Field

The invention relates to the technical field of sensors, in particular to a sensor sealing process.

Background

The sensor is a detection device, can feel the measured information, and can convert the felt information into an electric signal or other information output in a required form according to a certain rule so as to meet the requirements of information transmission, processing, storage, display, recording, control and the like, and the sensor is characterized by comprising: the sensor is a primary link for realizing automatic detection and automatic control, the existence and development of the sensor enable an object to have senses of touch, taste, smell and the like, the object slowly becomes alive, the object is generally divided into ten categories of thermosensitive elements, photosensitive elements, gas sensitive elements, force sensitive elements, magnetic sensitive elements, humidity sensitive elements, sound sensitive elements, radioactive ray sensitive elements, color sensitive elements, taste sensitive elements and the like according to the basic sensing function, people need to use sense organs to obtain information from the outside, the functions of people in researching natural phenomena and laws and producing and living the sense organs are far insufficient, and the sensor is needed to adapt to the situation, and the characteristics of the sensor comprise: the system is miniaturized, digitalized, intelligentized, multifunctional, systematized and networked, not only promotes the transformation and updating of the traditional industry, but also can establish novel industry, thereby becoming a new economic growth point in the 21 st century, the miniaturization is established on the basis of MEMS technology, the system is successfully applied to silicon devices to be made into silicon pressure sensors, and the sensors can be installed on a circuit board for detection.

The existing common glue dispensing is to drop a drop of glue on the surfaces of an MEMS and an ASIC respectively, the surface of the MEMS is transparent glue, the surface of the ASIC is black glue, the glue can prevent water vapor from entering from air holes in the front of a product, a small amount of water vapor falling on the surfaces of the MEMS and the ASIC does not play an effective role in protecting a bonding pad and a gold wire on a substrate in a high-temperature and high-pressure environment, and when the water vapor enters from the air holes and falls on two gold wires or two adjacent bonding pads, the product is easy to lose efficacy.

To this end, we propose a sensor sealing process.

Disclosure of Invention

The present invention has been made in view of the above and/or other problems associated with the prior art sensor sealing process.

Therefore, the invention aims to provide a sensor sealing process, which is characterized in that on the basis of a common process without any glue, a double-opening iron shell is packaged for protection, then glue is poured, bonding pads and gold wires can be effectively wrapped, only a pressure sensing unit is exposed, and water vapor is comprehensively isolated, so that the problem that the bonding pads and the gold wires on a substrate cannot be effectively protected by a small amount of water vapor falling on the surfaces of an MEMS and an ASIC in the high-temperature and high-pressure environment, and when the water vapor enters from an air hole and falls on two gold wires or two adjacent bonding pads, the product is easy to lose efficacy can be solved.

To solve the above technical problem, according to an aspect of the present invention, the present invention provides the following technical solutions:

a sensor sealing process, comprising: the circuit board, the glue injection hole, the metal cover and the exhaust hole are provided with the following operation steps:

s1: the sensor is assembled at the upper end of the circuit board, a metal cover is sleeved outside the pressure sensing unit, and the lower end of the metal cover is connected with the surface of the circuit board;

s2: the upper end of the metal cover is respectively provided with a glue injection hole and an exhaust hole, and the glue injection hole is arranged at the top of the sensor;

s3: aligning a glue injection needle head to a glue injection hole at the top of the sensor, lightly stepping on an automatic glue dispenser pedal, injecting a proper amount of glue into the glue injection hole through the glue injection needle head, allowing the glue to enter the metal cover through the glue injection hole, filling the inner space of the metal cover, extruding the air in the metal cover by the glue, discharging the air through an exhaust hole, checking whether the glue completely covers the sensor, arranging the circuit board in order after confirming that no fault exists,

s4: placing the circuit board with the dispensed glue on a baking and placing frame, pushing the baking and placing frame with the dispensed products into a baking box, and turning on a power supply of the equipment according to the requirement of an equipment operation instruction;

s5: after glue inside the metal cover is cooled and dried, firstly coating thinner three-proofing paint on the bottom of the metal cover and a connection part of a circuit board to ensure that no bubbles appear around the sensor, after 1 hour, coating undiluted three-proofing paint again, then coating the three-proofing paint on the outer wall of the metal cover, injecting glue into the glue injection hole to block the glue injection hole, and standing for 2 hours to completely dry the glue;

s6: adjusting the magnification of a microscope to 15-20 times, placing the circuit board which is painted for more than 2 hours under the microscope to check whether bubbles exist in sealing glue and painting on the surface of the sensor, marking a check mark at the specified position of the circuit board after the circuit board is qualified, and marking bad marks for bad products and recording the bad marks.

As a preferable aspect of the sensor sealing process of the present invention, wherein: in the step S3, the glue discharging time of the glue dispenser is set to be 2S, and the air pressure is set to be 20-25 PSI.

As a preferable aspect of the sensor sealing process of the present invention, wherein: in S3, the glue injection needle can not contact the sensor, the pedal of the glue dispenser is slightly stepped to completely cover the glue in the sensor, and the glue is ensured to completely cover the sensor hole.

As a preferable aspect of the sensor sealing process of the present invention, wherein: in the S3, the glue ratio is 1:1, and the stirring time is more than or equal to 2 minutes after the glue is prepared.

As a preferable aspect of the sensor sealing process of the present invention, wherein: and S3, after the circuit board is qualified through self-inspection, placing the circuit board on an anti-static partition plate for standing and cooling.

As a preferable aspect of the sensor sealing process of the present invention, wherein: in S4, the circuit boards are sequentially arranged according to the baking rack level and can not be stacked.

As a preferable aspect of the sensor sealing process of the present invention, wherein: in S4, the oven door must be closed and fastened during the baking operation.

As a preferable aspect of the sensor sealing process of the present invention, wherein: in the S4, the baking oven is set to 60 ℃ for 1 hour, and then set to 80 ℃ for 2 hours.

Compared with the prior art:

1. the appearance of the product is not changed, and no additional risk exists;

2. the gold wires and the bonding pads are protected, and product failure caused by external force is reduced;

3. the adhesive is perfect in dispensing and can completely isolate water vapor when working in a high-temperature and high-pressure environment;

through on ordinary not some any technological basis of gluing, the two opening iron-clad protections of encapsulation, then the encapsulating, can effectual parcel pad and gold thread, then do not play effectual protection to pad and gold thread on the base plate, only expose the forced induction unit, comprehensive isolated steam, make steam can not contact gold thread and pad, it is extremely difficult to cause the product to become invalid, during the injecting glue, the syringe needle contactless sensor, cover glue in the sensor completely, ensure that glue covers the sensor hole completely.

Drawings

FIG. 1 is an exploded view of the sensor sealing process of the present invention;

FIG. 2 is a top view of the metal cap installation in the sensor sealing process of the present invention.

In the figure: circuit board 1, injecting glue hole 2, metal covering 3, exhaust hole 4.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The invention provides a sensor sealing process, which has the advantages that a bonding pad and a gold wire are subjected to dispensing and wrapping, only a pressure sensing unit is exposed, and water vapor is completely isolated, and please refer to fig. 1, the sensor sealing process comprises a circuit board 1, a glue injection hole 2, a metal cover 3 and an exhaust hole 4;

further, the glue discharging time of the glue dispenser is set to be 2S, the air pressure is set to be 20-25PSI, and the model of the glue dispenser is ZX-983A.

Further, under the high-temperature and high-pressure environment, the glue injection needle head is aligned to the glue injection hole 2 in the top of the sensor, the glue injection needle head cannot contact with the sensor, the pedal of the glue dispenser is slightly stepped, glue is completely covered in the sensor, the sensor hole is completely covered by the glue, a proper amount of glue is injected into the glue injection hole 2 through the glue injection needle head, the glue enters the metal cover 3 through the glue injection hole 2, the inner space of the metal cover 3 is filled, the glue extrudes the air in the metal cover 3 and is discharged through the exhaust hole 4, whether the glue completely covers the sensor is checked, and the circuit board 1 is placed in order after the fact that no mistake occurs is confirmed.

Further, 527A/B mixed glue is set as glue, the glue ratio is 1:1, the glue mixed in a ratio of 1:1 and uniformly stirred in a ratio of 1:1 is poured into a needle cylinder of a dispenser, stirring time is required to be more than or equal to 2 minutes after the glue is prepared, after the glue in the metal cover 3 is cooled and dried, thinner three-proofing paint is firstly used for smearing the joint of the bottom of the metal cover 3 and the circuit board 1, no bubbles appear around the sensor, after 1 hour, undiluted three-proofing paint is reused for smearing once, then three-proofing paint is smeared on the outer wall of the metal cover 3, glue is injected into the glue injection hole 2 and blocked, and the glue is completely dried after standing for 2 hours.

Further, after the circuit board 1 is qualified through self-inspection, the circuit board 1 is placed on an anti-static partition plate to be kept stand and cooled, the magnification of a microscope is adjusted to be 15-20 times, the circuit board 1 which is placed for more than 2 hours after painting is placed under the microscope to check whether bubbles exist in sealing glue and painting on the surface of the sensor, after the circuit board 1 is qualified through inspection, inspection marks are made at the designated position of the circuit board 1, and bad products are marked and distinguished and bad records are made.

Furthermore, the circuit boards 1 are sequentially arranged according to the baking rack level and can not be stacked.

Furthermore, the oven door must be closed and fastened during the baking operation.

Further, the baking and placing frame for placing the products after dispensing is pushed into a baking box, the power supply of the equipment is turned on according to the requirements of the equipment operation instruction, the temperature of the baking box is set to be 60 ℃, the baking time is 1 hour, and then the temperature is set to be 80 ℃, and the baking time is 2 hours.

When the pressure sensing device is used specifically, the pressure sensing device works in a high-temperature and high-pressure environment, the first step is that the upper end of the circuit board 1 is provided with a sensor, the outer side of the pressure sensing unit is sleeved with a metal cover 3, and the lower end of the metal cover 3 is connected with the surface of the circuit board 1;

step two, the upper end of the metal cover 3 is respectively provided with a glue injection hole 2 and an exhaust hole 4, and the glue injection hole 2 is arranged at the top of the sensor;

step three, aligning the glue injection needle head to the glue injection hole 2 at the top of the sensor, slightly stepping on the pedal of the automatic glue dispenser, injecting a proper amount of glue into the glue injection hole 2 through the glue injection needle head, enabling the glue to enter the metal cover 3 through the glue injection hole 2, filling the inner space of the metal cover 3, extruding the air in the metal cover 3 by glue, discharging the air through the exhaust hole 4, checking whether the glue completely covers the sensor, placing the circuit board 1 neatly after no error is confirmed, setting the glue discharging time of the glue dispenser to be 2S, setting the air pressure to be 20-25PSI, preventing a glue injection needle head from contacting the sensor, slightly stepping on a pedal of the glue dispenser, completely covering the glue in the sensor, ensuring that the glue completely covers the sensor hole, wherein the glue ratio is 1:1, stirring time is required to be more than or equal to 2 minutes after the glue dispenser is prepared, and placing the circuit board 1 on an anti-static clapboard for standing and cooling after the circuit board 1 is qualified by self-inspection;

putting the circuit board 1 with the dispensed glue on a baking and placing frame, pushing the baking and placing frame with the dispensed products into a baking box, turning on a power supply of the equipment according to the requirement of an equipment operation instruction, sequentially placing the circuit boards 1 according to the layers of the baking frame, wherein the circuit boards cannot be stacked, closing and fastening a baking box door of the baking box during baking operation, setting the temperature of the baking box to be 60 ℃, baking time to be 1 hour, and then setting the temperature to be 80 ℃ and baking time to be 2 hours;

fifthly, after the glue inside the metal cover 3 is cooled and dried, firstly coating the joint of the bottom of the metal cover 3 and the circuit board 1 once by using thinner three-proofing paint to ensure that no bubbles appear around the sensor, after 1 hour, coating the undiluted three-proofing paint once again, then coating the three-proofing paint on the outer wall of the metal cover 3, injecting glue into the glue injection hole 2 to block the glue, and standing for 2 hours to be completely dried;

adjusting the magnification of the microscope to 15-20 times, placing the circuit board 1 which is painted and placed for more than 2 hours under the microscope to check whether bubbles exist in sealing glue and painting on the surface of the sensor, marking a check mark at a specified position of the circuit board 1 after the circuit board 1 is qualified, and marking bad marks for bad products and recording the bad marks; the operation needs to wear an electrostatic ring and gloves.

While the invention has been described above with reference to an embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the various features of the disclosed embodiments of the invention may be used in any combination, provided that no structural conflict exists, and the combinations are not exhaustively described in this specification merely for the sake of brevity and resource conservation. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.